The invention relates generally to a sashlock assembly and more particularly to a sashlock assembly which includes a key lock to retain the sashlock in a latched position.
In a double hung window assembly a pair of sashes are mounted in a frame and movable vertically to open or close the window. When the window is closed, usually there is only a small gap, if any, between the top rail of the lower sash and the bottom rail of the top sash.
A sashlock assembly is commonly used with double hung windows. When the window assembly is closed, the sashlock assembly is shifted from an unlatched position to a latched position to keep the window closed. A sashlock assembly usually includes a sashlock mounted on the top rail of the bottom sash and a keeper mounted on the bottom rail of the top sash. The rails may provide horizontal mounting surfaces on the respective sashes that are flush when the window is closed. In some applications, especially with extruded vinyl or aluminum sash rails, the keeper or the sashlock or both may be secured to vertical surfaces or to specially formed slots or recesses in the rails.
A sashlock typically comprises a housing and a rotating assembly which includes a rotating member and a lever. The rotating member, usually a cam, is mounted to the housing for rotation between an unlatched position and a latched position. The lever is operably connected to the cam and extends outside of the housing so that the cam may be conveniently moved between the latched and unlatched positions. When the sashlock is in the unlatched position, the cam is retracted and thus disengaged from the keeper, and the sashes may be moved relative to each other. When the sashlock is in the latched position, a portion of the cam engages the keeper to prevent movement of the sashes.
Unfortunately, sashlocks are sometimes vulnerable to unauthorized tampering from the outside of the building which shifts the sashlock from the latched to the unlatched position. For example, with some prior art sashlocks, it is possible from the outside of the building to insert a blade into the gap between the two sashes, engage the cam with the blade, and force the cam back to its unlatched position. The window may then be opened from the outside of the building to provide access into the building.
The present invention provides a lockable sashlock assembly which eliminates, or at least reduces the chances of, successful unlatching of the sashlock from outside the building. Particularly, the invention provides a lockable sashlock assembly which may be locked in the latched condition. In this specification the terms xe2x80x9clatchedxe2x80x9d and xe2x80x9cunlatchedxe2x80x9d are used with reference to the engagement between the cam of the sashlock and the keeper. The terms xe2x80x9clockedxe2x80x9d and xe2x80x9cunlockedxe2x80x9d are used with reference to a safety lock device used to hold the cam in its latched position.
The lockable sashlock assembly according to the present invention includes a sashlock having a rotating device and a safety lock mechanism. The rotating device (usually a cam) is movable between an unlatched position in which the window assembly is openable and a latched position in which the window assembly is unopenable. The safety lock mechanism has a locked state in which the rotating device is retained in its latched position, thus securing the window assembly against forced entry. The safety lock mechanism may be switched to an unlocked state in which the rotating device is free to turn between its latched and unlatched states. The locking mechanism includes a key slot and is convertible from the locked state to the unlocked state upon insertion of an appropriately shaped key in the key slot.
Accordingly, the sashlock assembly may be locked so that even if a blade is inserted into the gap between the two sashes to engage the rotating member, it will still not be possible to force the cam back to its unlatched position. Additionally, since in the preferred embodiment a key is necessary to turn the safety lock mechanism to the unlocked state, the lockable sashlock assembly according to the present invention can also be used to control window openings inside the building. For example, if a facility""s regulations forbid the opening of windows in certain designated areas, the relevant sashlocks can be placed in the locked state and only authorized personnel provided with the key.
The invention comprises these and other features hereinafter fully described in the specification and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be suitably employed.